There, is growing societal concern about the physical inactivity of children and the detrimental affects this may be having on their physical and mental development. Research also suggests there is an increasing rate of obesity amongst the young.
There is therefore a demand for play equipment that will engage children and in doing so encourage physical activity, increase skills, creativity and social interaction. This equipment must be safe to minimise the likelihood of serious accidents, whilst still stimulating the children physically and engaging them mentally. It is also desirable for the equipment to be robust enough to continue operating despite physical impacts and weathering.
It has been observed that interactive play equipment that incorporates moving elements is more likely to engage children and maintain that engagement for a longer period of time than static or non-interactive equipment. Equipment involving climbing inherently provides an elevated exercise dimension over comparable equipment operated at a substantially fixed level. Equipment such as slides, poles or the like, also entices the user to repetitive or cyclic climbing and descending the equipment as a natural part of play.
Thus, in many operations, including play, it is useful to lower a user from an elevated position to a lower position, e.g. as in use of a pole or slide. This may incur an inherent and uncomfortable friction experienced by the user using poles, slides or the like. Consequently, attempts have been made to reduce friction and increase comfort of slides etc with varying degrees of success.
It would thus be advantageous to provide play equipment that reduces or eliminates friction experienced by a user during descent.
The operating principles of such play equipment are of course also applied in other fields such as industry (e.g. packaging chutes), workplaces (e.g. fireman's pole) and home (lifts and slides for the disabled). Therefore, while the present invention and related art may be described herein with respect to play or exercise equipment, it should be appreciated that this disclosure is not limited to same and includes equivalent mechanisms in other applications.
The following paragraphs describe devices and systems that are of general relevance to the present invention and describe various mechanisms in the art for lowering/raising a person or object. All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country.
U.S. Pat. No. 3,252,547 by Homedo describes a lift or elevator which uses a lift platform positioned above and rigidly joined to a buoyant tank floating in a water reservoir. The lift lowers when the lift occupants' weight exceeds the upward buoyancy force. Homedo's disclosure is silent on how the lift rises with occupants present that weigh more than the buoyancy force, though from an engineering perspective, this may be achieved in a variety of means, e.g. the buoyancy of the tank is varied by pumping water in/out. However, the Homedo elevator is necessarily tall so as to provide space for a large enough water reservoir and tank to support the lift and occupants and to move the occupants between floors. Moreover, as the elevator shaft may be considerably tall, the water reservoir would have to extend a commensurate distance below ground level in order to lower the lift to ground level. The Homedo elevator is thus clearly expensive and unsuitable for playground use or other smaller-scale applications.
Other elevator or descent mechanisms that use buoyancy to control lift and descent are described in Japanese Patent Publication No. 10-201812 by Yasunari, U.S. Pat. No. 4,069,923 by Blumenau, PCT Publication No. WO86/02544 by Boublil and Great Britain U.S. Pat. No. 1,370,610 by Adamson. However, in contrast to the Homedo elevator, these elevators allow the elevator platform to be lowered below water level, though the platform is necessarily submerged. Thus, these devices are not useful where the user does not want to get wet.
One device that may be suitable for small-scale lift applications is described in PCT application published as WO2008/030117 by McConnell. This document describes a decorative water feature (which may be used as a lift) where a sliding platform encircles a tube within which a float is positioned in a column of water or other liquid. The float and platform are coupled together for common movement by a mutual magnetic attraction/repulsion. Thus, as the float moves, so does the platform and vice versa.
However, the McConnell magnetic water feature would require strong magnets to operate as a lift for persons and could therefore be prohibitively expensive for playground and other applications.
In many exercise machines, the working resistance is applied by external weights or by the user's own weight. The attendant problem with the user working against their own weight is that a person's strength is not always proportional to their weight; e.g. the elderly, overweight and those with a disability are likely to have a lower strength to weight ratio which may make moving their own weight unfeasible, even with force reduction mechanisms. At the opposite end of the fitness spectrum, relying solely on the user's mass for resistance has an inherent upper limit which may be insufficiently high for individuals with a high power to weight ratio. It would therefore be advantageous to provide a robust and safe recreational exercise apparatus and/or lift/elevator.
It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice.
It is acknowledged that the term ‘comprise’ may, under varying jurisdictions, be attributed with either an exclusive or an inclusive meaning. For the purpose of this specification, and unless otherwise noted, the term ‘comprise’ shall have an inclusive meaning—i.e. that it will be taken to mean an inclusion of not only the listed components it directly references, but also other non-specified components or elements. This rationale will also be used when the term ‘comprised’ or ‘comprising’ is used in relation to one or more steps in a method or process.
Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.